Modeling of Nonlinear Active Circuits Using FDTD Approach

This paper, describes a voltage- source formulation of the extended finite-difference time-domain algorithm for the purpose of modeling nonlinear microwave devices. Based on this approach, the device-wave interaction is characterized and incorporated into FDTD algorithm. Analysis of nonlinear properties, including harmonic generation and intermodulation, can be accomplished by using a large signal device circuit model. This technique is applied to the analysis of a typical nonlinear microwave amplifier, which includes a three-terminal active MESFET device. Simulation results are in good agreement with MICROWAVE OFFICE results.